The Animal Liberation Front, an FBI-certified domestic terrorist organization started in Great Britain by "hunt saboteurs" looking to interrupt or otherwise ruin organized fox hunts. Today's ALF is active in more than 20 countries, engaging in violent "direct actions" against restaurants, meat & dairy producers, animal entertainment companies, fur retailers, biomedical research labs, and others. Attacks have included massive arsons, bombings, physical assaults, and death threats. The FBI considers the ALF America's most serious domestic terror problem, ranking it above the Ku Klux Klan, the Aryan Nation, and Operation Rescue (known for bombing family-planning clinics). In the United States, groups that have financially supported or publicly endorsed the ALF include People for the Ethical Treatment of Animals and Farm Sanctuary.